scholarly journals Evaluation of the Effect of Various Antioxidants on the Shear Bond Strength of the Composite Resin to the Bleached Enamel: An In Vitro study

Author(s):  
Somya Jain ◽  
Neetu Jindal ◽  
Renu Agarwal ◽  
Ajisha Raju ◽  
Shallu Bansal

Abstract Objective Various intrinsic and extrinsic stains cause discolored teeth, which is of great concern to patients, which can be treated by bleaching, enamel microabrasion, veneers, and crowns. However, bleaching leads to reduced bond strength if adhesive restorations are performed immediately.Thus, the application of antioxidant agents after bleaching has been recommended, which are proved to act as free radical scavengers, improving the bond strength. Materials and Methods A total of 120 extracted human maxillary incisor teeth were taken. Using a slow-speed diamond saw and a water coolant spray, the roots of all the teeth were removed approximately 2 mm below the cementoenamel junction. With the labial surface facing upward, each sectioned sample was embedded in the acrylic resin. Then, the central portion of the embedded tooth was ground flattened with 600-grit silicon carbide paper such that the labial enamel surface becomes smooth and evenly flat.All 120 samples were divided into two control groups (n = 20), i.e., positive control group (n = 10) and negative control group (n = 10) and five experimental groups (n = 100), such that each experimental group had 20 samples.The enamel surface in both the control groups and groups treated with antioxidants was thoroughly rinsed off with distilled water for 30 seconds and subjected to bonding procedure. Result Significant differences were observed among the experimental groups (p < 0.05). The samples that were treated with 10% sodium ascorbate (group III) demonstrated significantly higher mean shear bond strength than the other experimental groups (p < 0.05).

2016 ◽  
Vol 10 (01) ◽  
pp. 109-115 ◽  
Author(s):  
Mahendran Kavitha ◽  
Sharmila Selvaraj ◽  
Ambica Khetarpal ◽  
Aruna Raj ◽  
Shakunthala Pasupathy ◽  
...  

ABSTRACT Objective: The aim of this study was to investigate the neutralizer effect of antioxidant agents on the bond strength of bleached enamel. Materials and Methods: Sixty enamel slabs were prepared from 60 freshly extracted maxillary central incisors and were divided into six groups. The negative control group received no bleaching treatment and the other groups were bleached with 35% carbamide peroxide (Opalescence Quick; Ultradent, South Jordan, USA). In Group II, composite was built immediately after bleaching and cured without any antioxidants. In Group III, bleached specimens received composite build ups delayed by 1 week. In Groups IV, V, and VI bleached specimens received applications of superoxide dismutase (SOD), sodium ascorbate (SA), and tocopherol solutions, respectively, for 10 min. Following composite bonding, the micro shear bond strength (μSBS) was measured at a speed of 1 mm/min in universal testing machine. Statistical Analysis Used: The μSBS values of all the groups were analyzed using the analysis of variance followed by Tukey honestly significant difference post-hoc test. Results: Bonding of composites to unbleached group (Group I) exhibited the highest mean SBS values and among the antioxidant-treated groups, the highest SBS values were seen with SOD (Group IV) treated samples (23.0040 ± 4.30565 MPa). Conclusions: Application of SA, alpha-tocopherol, and SOD can effectively reverse the bond strength with bleached enamel. SOD gave a comparatively more promising reversal of bond strength than SA and alpha-tocopherol, and deserves further studies.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yomna A. Nabawy ◽  
Tarek N. Yousry ◽  
Nadia M. El-Harouni

Abstract Background Increased risk of enamel demineralization during and after orthodontic treatment raises the demand for better preventive measures including combinations of laser, CPP-ACP, and fluoride. The combination of Er,Cr:YSGG laser with CPP-ACP was proved to have a synergetic effect compared to each of them alone. Shear bond strength (SBS) of orthodontic brackets bonded to the enamel surface after being treated with preventive measures is critical. The aim of this study was to compare the SBS and failure mode of metallic brackets bonded to teeth with no pretreatment and pretreated enamel surface, either with Er,Cr:YSGG laser alone or combined with CPP-ACP. Methods Sixty sound extracted human premolar teeth were allocated randomly to 3 groups: In Group 1 (control), teeth were etched and bonded directly; in Group 2, laser pretreatment of the enamel surface was done followed by etching and bonding as in the control group; in Group 3, the enamel surface was lased then CPP-ACP was applied according to the manufacturer instructions, etched and bonded. SBS and Adhesive remnant index (ARI) were evaluated. Results No significant differences were found between the 3 groups neither in the SBS nor in the ARI scores. Conclusions The use of combined Er,Cr:YSGG laser with CPP-ACP as a preventive measure before bonding orthodontic brackets does not endanger the bracket’s bonding strength.


2015 ◽  
Vol 40 (3) ◽  
pp. E112-E121 ◽  
Author(s):  
HA St Germain ◽  
TH St Germain

SUMMARY In this laboratory research, shear bond strength (SBS) and mode of failure of veneers rebonded to enamel in shear compression were determined. Three groups (A, B, and C; n=10 each) of mounted molar teeth were finished flat using wet 600-grit silicon carbide paper, and 30 leucite-reinforced porcelain veneers (5.0 × 0.75 mm) were air abraded on the internal surface with 50 μm aluminum oxide, etched with 9.5% hydrofluoric acid, and silanated. The control group (A) veneer specimens were bonded to enamel after etching with 37% phosphoric acid using bonding resin and a dual cure resin composite cement. Groups B and C were prepared similarly to group A with the exception that a release agent was placed before the veneer was positioned on the prepared enamel surface and the resin cement was subsequently light activated. The debonded veneers from groups B and C were placed in a casting burnout oven and heated to 454°C/850°F for 10 minutes to completely carbonize the resin cement and stay below the glass transition temperature (Tg) of the leucite-reinforced porcelain. The recovered veneers were then prepared for bonding. The previously bonded enamel surfaces in group B were air abraded using 50 μm aluminum oxide followed by 37% phosphoric acid etching, while group C enamel specimens were acid etched only. All specimens were thermocycled between 5°C and 55°C for 2000 cycles using a 30-second dwell time and stored in 37°C deionized water for 2 weeks. SBS was determined at a crosshead speed of 1.0 mm/min. SBS results in MPa for the groups were (A) = 20.6±5.1, (B) = 18.1±5.5, and (C) = 17.2±6.1. One-way analysis of variance indicated that there were no significant interactions (α=0.05), and Tukey-Kramer post hoc comparisons (α=0.05) detected no significant pairwise differences. An adhesive mode of failure at the enamel interface was observed to occur more often in the experimental groups (B = 40%, C = 50%). Rebonding the veneers produced SBS values that were not significantly different from the control group. Also, no significant difference in SBS values were observed whether the debonded enamel surface was air abraded and acid etched or acid etched only.


2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Sofia Lobo ◽  
Inês Caetano Santos ◽  
António H. S. Delgado ◽  
Luís Proença ◽  
Mário Polido ◽  
...  

AbstractThe aim was to evaluate the effect of different antioxidant agents on the improvement of bond strength to enamel subjected to a whitening procedure. Samples were divided into six groups (n = 10): control; whitening immediately followed by restorative treatment (WHT); whitening and restoration after a 7-day period (WHT_7D); whitening and application of 10% sodium ascorbate (WHT_SA); application of 5% grape seed extract (WHT_GS); and application of 5% green tea (WHT_GT). All groups except for control fwere whitened (Opalescence PF Regular 16%) for 7 days (4 h/day). All samples were restored (Optibond™ FL, Kerr and Filtek™ Z250 composite, 3M ESPE). In antioxidant groups these were applied for 15 min and immediately restored. Specimens were sectioned in microspecimens (1.0 ± 0.2 mm2 area) for microtensile bond strength (μTBS) testing (0.5 mm/min) on a universal testing machine. ANOVA test with Brown-Forsythe correction and Games-Howell post-hoc test was used (significance level of 5%). Antioxidant groups presented significant higher mean μTBS values than group WHT (p < 0.001). The non-whitened control group was not significantly different to antioxidant experimental groups. Group WHT_7D exhibited a significantly higher mean μTBS value when compared to group WHT (p = 0.022). The different antioxidants significantly influenced microtensile bond strength of restored teeth after whitening.


2020 ◽  
Vol 25 (5) ◽  
pp. 38-43
Author(s):  
Juan Fernando Aristizábal ◽  
Angela Patricia Polanía González ◽  
James A. McNamara

ABSTRACT Objective: To evaluate a protocol for bonding metallic brackets after bleaching with hydrogen peroxide (HP). Methods: 60 extracted maxillary premolar were randomly divided into an unbleached control group and two groups bleached with a solution of 35% hydrogen peroxide prior to bonding. The teeth in one of the treated groups were bonded immediately after bleaching; while the other group was treated with 10% sodium ascorbate immediately after bleaching and before bonding. The teeth in all groups were stored in an artificial saliva solution for 7 days after bonding. The shear bond strength data was measured in megapascals (MPa) and the fail attempts were verified. The significance level was established at p< 0.05. Results: The unbleached group, in which brackets were bonded to untreated enamel, had the highest bond strength values (11.0 ± 5.7MPa) in comparison to the bleached group (7.14 ± 40MPa), in which brackets were bonded to recently bleached enamel. Slightly improved bond strength was observed in the antioxidant group (8.13 ± 5.4MPa), in which the teeth were bleached and then the antioxidant was applied to the teeth before bonding. Unbleached and bleached groups showed statistically significant difference for shear bond strength (p=0.03) and load strength (p=0.03); no significant differences were noted between unbleached and antioxidant groups (p=0.52). Conclusion: The antioxidant treatment applied immediately after bleaching was effective in reversing the reduction in shear bond strength of brackets after tooth bleaching.


2017 ◽  
Vol 22 (4) ◽  
pp. 53-60 ◽  
Author(s):  
Nasrin Farhadian ◽  
Loghman Rezaei-Soufi ◽  
Seyed Farzad Jamalian ◽  
Maryam Farhadian ◽  
Shahrzad Tamasoki ◽  
...  

ABSTRACT Introduction: Many patients seeking orthodontic treatment already have incipient enamel lesions and should be placed under preventive treatments. The aim of this in vitro study was to evaluate the effect of CPP-ACP paste and CO2 laser irradiation on demineralized enamel microhardness and shear bond strength of orthodontic brackets. Methods: Eighty caries-free human premolars were subjected to a demineralization challenge using Streptococcus mutans. After demineralization, the samples were randomly divided into five equal experimental groups: Group 1 (control), the brackets were bonded without any surface treatment; Group 2, the enamel surfaces were treated with CPP-ACP paste for 4 minutes before bonding; Group 3, the teeth were irradiated with CO2 laser beams at a wavelength of 10.6 µm for 20 seconds. The samples in Groups 4 and 5 were treated with CO2 laser either before or through CPP-ACP application. SEM photomicrographs of a tooth from each group were taken to observe the enamel surface. The brackets were bonded to the buccal enamel using a conventional method. Shear bond strength of brackets and ARI scores were measured. Vickers microhardness was measured on the non-bonded enamel surface. Data were analyzed with ANOVA and Tukey test at the p< 0.05 level. Results: The mean shear bond strength and microhardness of the laser group were higher than those in the control group and this difference was statistically significant (p< 0.05). All groups showed a higher percentage of ARI score 4. Conclusion: CO2 laser at a wavelength of 10.6 µm significantly increased demineralized enamel microhardness and enhanced bonding to demineralized enamel.


2015 ◽  
Vol 26 (1) ◽  
pp. 61-65 ◽  
Author(s):  
Monique Kruger Guarita ◽  
Alexa Helena Köhler Moresca ◽  
Estela Maris Losso ◽  
Alexandre Moro ◽  
Ricardo Cesar Moresca ◽  
...  

The aim of this study was to evaluate the shear bond strength of rebonded ceramic brackets after subjecting the bracket base to different treatments. Seventy-five premolars were selected and randomly distributed into five groups (n=15), according to the type of the bracket surface treatment: I, no treatment, first bonding (control); II, sandblasting with aluminum oxide; III, sandblasting + silane; IV, silica coating + silane; and V, silicatization performed in a laboratory (Rocatec system). The brackets were fixed on an enamel surface with Transbond XT resin without acid etching. The brackets were then removed and their bases were subjected to different treatments. Thereafter, the brackets were fixed again to the enamel surface and the specimens were subjected to shear bond strength (SBS) test. The adhesive remnant index (ARI) was then evaluated for each specimen. Data were subjected to ANOVA and Tukey's tests (α=0.05). A statistically significant difference was observed only between Rocatec and the other groups; the Rocatec group showed the lowest SBS values. The highest SBS values were observed for group 1, without any significant difference from the values for groups II, III and IV. Most groups had a higher percentage of failures at the enamel-resin interface (score 1). It was concluded that the surface treatments of rebonded ceramic brackets were effective, with SBS values similar to that of the control group, except Rocatec group.


2016 ◽  
Vol 10 (1) ◽  
pp. 720-727 ◽  
Author(s):  
Ladan Ranjbar Omrani ◽  
Parastoo Sabouri ◽  
Mehdi Abbasi ◽  
Elham Ahmadi ◽  
Maryam Ghavam

Background: Studies have shown a reduction in bond strength of composites and glass ionomer to bleached enamel and dentin. Several methods have been proposed to reverse compromised bond strength. Objective: The aim of this study was to evaluate the effect of delayed bonding and application of antioxidant agent on the bond strength of reinforced self-cured (Fuji IX) and light-cured glass ionomers (Fuji II LC) to bleached dentin. Material: Eighty extracted third molars were randomly divided into 8 groups. Buccal dentin surfaces received different treatments: Two control groups: no treatment + bonding Fuji IX or Fuji II LC. Two immediate bonding groups: bleaching + bonding Fuji IX or Fuji II LC. Two delayed bonding groups: bleaching + 7 days delay + bonding Fuji IX or Fuji II LC. Two sodium ascorbate application groups: Bleaching + application of 10% sodium ascorbate + bonding Fuji IX or Fuji II LC. All samples were tested for shear bond strength. Two-way analysis of variance (ANOVA) was used to compare the mean and standard deviations among groups, followed by the Tukey’s test for significant interaction. Results: No statistically significant difference was detected in shear bond strength of Fuji IX to bleached or normal dentin. Although a significant reduction was found shear bond strength values of Fuji II LC to bleached dentin, no significant difference was observed between no bleaching group and those treated with 10% sodium ascorbate or 7 days of delay in bonding for both types of glass ionomer. Conclusion: Bleaching had no significant effect on shear bond strength of Fuji IX to dentin; this type of GI can be used immediately after bleaching.


2022 ◽  
Vol 9 (1) ◽  
pp. 20
Author(s):  
Riccardo Beltrami ◽  
Marco Colombo ◽  
Andrea Cavada ◽  
Sofia Panizzi ◽  
Claudio Poggio ◽  
...  

In the present study, we evaluated the influence of bovine enamel exposure to acidic drinks (Coca-Cola, Coca-Cola Company, Milano, Italy, pH = 2.37) on shear bond strength of three sealants (Fissurit; Grandio Seal and Admira Fusion—Voco Gmbh, Cuxhaven, Germany). For each sealant, two adhesive techniques were tested to investigate the impact of the adhesive application on shear bond strength of sealants after immersion in acidic drink and in the control: Group 1—Control: enamel surface was not in contact with acid drinks, acid etching application and self-adhesive technique for fissure sealant; Group 2—enamel surface was not in contact with acid drinks, acid etching, and adhesive applications, an etch-and-rinse technique for fissure sealant; Group 3—enamel surface was immersed in acid drink, acid etching application and self-adhesive technique for fissure sealant; Group 4—enamel surface was immersed in acid drink, acid etching, and adhesive applications, an etch-and-rinse technique for fissure sealant. For each specimen, the sealant composite resin was applied to the enamel surface and tested with a universal testing machine. Shear bond strength was measured in MPa and with an optical microscope to determine failure modes, quantified with adhesive remnant index (ARI). Enamel acidification variably influenced bond strength values of the different sealants. When no enamel pretreatment was applied, no significant differences were found among the sealants (p > 0.05). However, the mere application of acid etching without adhesive procedures resulted in lower bond strength (p < 0.001). The acid pretreatment affected significantly the bond strength of all sealants tested (p < 0.001), but no significant differences were recorded between the subgroups.


2015 ◽  
Vol 40 (5) ◽  
pp. 548-557 ◽  
Author(s):  
C Sabatini ◽  
Z Wu

SUMMARY Background Desensitizing agents are used, almost as routine practice, in many adhesive restorative procedures. There is still debate as to their effect in dentin bonding, particularly with self-etching adhesives. The present study aimed to evaluate the effect of different desensitizing agents on the bond strength of mild and strong self-etching adhesive systems to dentin. Materials and Methods One hundred twenty recently extracted, noncarious human molars were used to obtain superficial dentin substrate for bonding. No desensitizer was used in the control groups. The experimental groups were pretreated with Gluma Desensitizer, MicroPrime B, and Dentin Desensitizer immediately prior to bonding with self-etching adhesives Optibond XTR, Xeno IV, and iBond. A bonding jig was used to fabricate composite cylinders, which were stored for either 24 hours or three months, after which the shear bond strength (SBS) was evaluated using a notched-edge testing device at a crosshead speed of 1 mm/min. Failure mode distribution was also evaluated at 24 hours and three months. A two-way analysis of variance, Tukey test, and Student t-test, with a significance level of p&lt;0.05, were used for data analysis. Results At 24 hours, there was no significant difference in SBS when the same adhesive was used with any of the experimental desensitizing agents compared with the control group without desensitizer. However, at three months, Dentin Desensitizer bonded with Optibond XTR demonstrated significantly lower SBS (p&lt;0.001), while Gluma bonded with iBond showed significantly higher SBS values (p=0.034) relative to their corresponding control group. Only MicroPrime B bonded with Xeno IV and iBond with no desensitizer demonstrated a significant reduction in SBS after three months (p=0.034 and p=0.002, respectively). The most prevalent type of failure was adhesive. Conclusion Desensitizing agents can be used in combination with self-etching adhesives to control hypersensitivity without adversely affecting their bond strength to dentin.


Sign in / Sign up

Export Citation Format

Share Document